Extraction of three tanshinones from the root of Salvia miltiorrhiza Bunge by supercritical carbon dioxide fluid and their analysis with high performance liquid chromatography

The extraction of three tanshinones from the root of Salvia miltiorrhiza Bunge by supercritical carbon dioxide (SC CO 2) fluid with ethanol as co solvent was investigated using four factor and three level orthogonal design method and the systematic method The optimized conditions were established as follows: 95% ethanol was selected as a co solvent, flow rate of co solvent was 1 0 mL/min, extraction pressure was 20 MPa, extraction temperature was 45 ℃,separation temperature was 35 ℃. The sample solution was separated on a Nova Pak C 18 column (3 9 mm i d ×300 mm,5 μm)with CH 3OH H 2O (80∶20, V/V ) as the mobile phase and detected at 280 nm The correlation coefficients were 0 999?4-0 999?8 and the relative standard deviations were 2 37%-3 47% The detection limits were 0 473 mg/L, 0 184 mg/L and 0 452 mg/L for tanshinone ⅡA, tanshinone Ⅰ and cryptotanshinone respectively